Mr Justice Treacy is being asked to decide whether human life begins before birth, when a foetal heartbeat is detected.

If his judgment indicates whether the rights of a person exist before birth, it may have profound implications for abortion law.

The case is being brought by lawyers acting for John Larkin, the attorney-general, on Ms Desmond's behalf.

The issue brings back comments Mr Larkin made in a BBC radio discussion in 2008.

Mr Larkin said "if one is prepared to contemplate the destruction of a highly disabled, unborn child in the womb, one should also be prepared to contemplate, I think, putting a bullet in the back of the head of the child two days after it's born."

That was well before he took office and, since we had no attorney-general then, he could not have known that he was even being considered for his future post.

Yet his vivid and controversial remarks are bound to be remembered in the context of this court case, which explores the fraught area of when human life begins.